According to the news of the South China Morning Post, Chinese archaeologists, Japanese scientists, II. They discovered an underground “dreadful bunker” that they used to conduct brutal human experiments before and during World War II.

The facility, near Anda, China, is believed to have been used by the 731st Division of the Imperial Japanese Army to conduct brutal human experiments between 1935 and 1945.

Japanese scientists exposed prisoners to pathogens and dissected them to learn about their effects on the human body. The findings were used by the Imperial Japanese Army to spread typhus, cholera and plague in China, the newspaper reported.

The infamous unit tried and killed thousands of people, including men, women, and children.

The study, published in May in the journal Northern Cultural Relics, may provide new evidence of war crimes.

“It also highlights the continued legacy of Unit 731’s brutality and their impact on global efforts to prevent biological warfare,” said researchers from the Heilongjiang Provincial Institute of Cultural Relics and Archeology.

Archaeologists discovered the underground structure, which consists of several interconnected tunnels and chambers, after starting their investigation in 2019 using geophysical exploration, drilling and excavation methods.

The South China Morning Post reported that researchers have not yet penetrated the bunkers, but the study has revealed details of the underground structures.

Five feet below the surface, a U-shaped cluster of bunkers and a circular chamber were discovered that archaeologists believe were used to observe and study people after they were infected with pathogens or chemicals.

The researchers said their knowledge of the subterranean object is still in its preliminary stages and more needs to be done to learn how the structures are connected.

Archaeologists say most of the above-ground buildings at the Anda site were demolished in 1945 to erase evidence of the experiments, but the underground structures remained.

According to the report, facilities such as barracks, Turkish baths and dining halls were built underground to protect privacy.

Some Unit 731 investigators were reportedly arrested by the Soviets and tried for war crimes at the Khabarovsk Trials of December 1949, while those captured by the United States reportedly received immunity in exchange for their investigations.